Modular building system

ABSTRACT

Modular building units are fabricatd from metal parts to form tubular sections having a rectangular cross section and variable length. The modular units are placed side by side and stacked to form a multi-story dwelling. The ends of the modules are closed with a rigid insulating material, and the sides, bottoms and tops are perforated where required for installation of doors, windows and staircases and to permit access from one module to another. The metal parts are trough shaped for increased strength, and the sides, bottoms and tops are interconnected by four channel members, which extend the entire length of the modules. The inside surfaces of the sides and tops are lined with gypsum board or some other suitable non-combustible material, and the inside surfaces of the bottoms are covered with particle board or the like. Gypsum board diaphragms are placed at suitable positions along the modules to define rooms or to divide the modules into a plurality of dwelling units. The modules are secured together and a roof section is placed above the stacked modules after which insulation and siding are placed around the exterior surfaces of the dwelling.

United States Patent [191 Hughes [451 Feb. 26, 1974 g [76] Inventor:

[ MODULAR BUILDING SYSTEM Robert Hughes, 26 Beaconsfield Blvd., Beaconsfield, Quebec, Canada [22] Filed: Sept. 24, 1971 [21] Appl. N0.: 183,343

Primary Examiner-John E. Murtagh Attorney, Agent, or Firm-Kane, Dalsimer, Kane, Sullivan and Kurucz 57 1 ABSTRACT Modular building units are fabricatd from metal parts to form tubular sections having a rectangular cross section and variable length. The modular units are placed side by side and stacked to form a multi-story dwelling. The ends of the modules are closed with a rigid insulating material, and the sides, bottoms and tops are perforated where required for installation of doors, windows and staircases and to permit access from one module to another. The metal parts are trough shaped for increased strength, and the sides, bottoms and tops are interconnected by four channel members, which extend the entire length of the modules. The inside surfaces of the'sides and tops are lined with gypsum board or some other suitable noncombustible material, and the inside surfaces of the bottoms are covered with particle board or the like. Gypsum board diaphragms are placed at suitable positions along the modules to define rooms or to divide the modules into a plurality of dwelling units. The modules are secured together and a roof section is placed above the stacked modules after which insulation and siding are placed around the exterior surfaces of the dwelling.

12 Claims, 13 Drawing Figures PATENTED FEBZB i974 sum 1 0F 7 INVENT R ROEEFT #0 was PATENTEDFEB26 1914 sum 2 or 7 INVENTOR 9035??" Hum SHEET 5 OF 7 FIG. /0

. "1 MODULAR BUILDING SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention Thisinvention relates to building construction and more particularly, to buildings constructed from standard prefabricated modules.

2. Description of the Prior Art Because of the population explosion, there presently exists an acute housing shortage, which cannot be satisfied by standard building techniques. l-leretofore, buildings were essentially constructed at the building site with the exception of a relativelyfew prefabricated units. The prefabricated units had prefabricated frames only and the interior was completely unfinished. Most prefabricated units consisted of wood frame walls, which were assembled at the construction site after which the interior finish was added. The inherent characteristics of wood frame construction made it impossible to construct a truly rigid and square wall; therefore, the interior could not be finished in prefabricated form. Thus, expensive on-site labor was required and the cost increased.

In order to satisfy the present housing need, the techniques of the mass production must be applied to the building industry. This requires that the buildings be assembled as completely as possible-at one central location where mass production and automated techniques can be applied and where unskilled labor can be utilized to the greatest extent possible. The factory assembled units must be readily transportable by rail and highway transportation to the actual building site; therefore, size limitations are'dictated by the available highway and railroad facilities.

Because of the high cost of land and the lack of available space, it is essential that dwelling units be designed for relatively high density occupancy; and it is therefore required that modular building units be selfsupporting and have the capability of supporting similar units.

Modern building codes also dictate the future dwelling units of the high density type must be as noncombustible as possible to prevent fire disasters.

A practical modular building system must be designed to have the capability of being combined in a variety of ways to make houses, hotels, dormitories, hospitals, schools and other kinds of shelter. Therefore, a basic building system is required that can easily be modified for specific applications and individual requirements.

SUMMARY OF THE INVENTION channels, which run the entire length of the tubular section. The use of steel is preferred because of its strength and non-combustible characteristics. The steel components are trough shaped to provide added strength so that a minimum gauge steel may be used for the construction. The trough-shaped steel components provide sufficient strength so that units are selfsupporting and capable of supporting other similar units. Thus, the modules may be stacked to form multiple dwelling houses. The trough-shaped components have returned side flanges that are welded together to simulate a joist and floor board construction, which provides convenient space for running electrical wires, plumbing and insulation should it be desired.

The tubular sections have perforations in the sides, bottom and top where required to permit the installation of doors, windows and staircases and to provide access from one module to another.

A diaphragm of laminated gypsum board divides each module into a left and a right section, the left section forming a portion of a one family dwelling, the right section forming a portion of another one family dwelling. Laminated gypsum board panels are also used to close the ends of the tubular sections.

The inside surfaces of the side walls and the top of each module are lined with gypsum board at the factory, and the inside of the bottom has a factory installed particle board material attached thereto, which serves as a flooring.

A typical two-family dwelling unit may be con structed by the use of six separate modules stacked two high and three deep with the tubular sections extending across the dwelling from left to right. After the modules are connected at the building site, the exterior surfaces are covered with insulation and a suitable weather resistant exterior siding material and a roof having a weather resistant top surface is installed. Thereafter, interior trim and a finished floor surface such as vinyl tile is installed to complete the dwelling. Thus, a finished house is similar in appearance to conventional houses both on the inside and outside.

The primary objective of the present invention is to provide a building module that may be combined with other such modules to form a building.

Another objective of the present invention is to provide a building module that is factory produced from standard components and which may be combined at a building site to construct houses, hotels, dormitories,-

hospitals, schools and other such shelters.

Another objective of the present invention is to provide a building module that is selfisupporting and has the capability of supporting similar modules.

' Another objective of the present invention is to provide a building module that has a size compatible with present highways and rail transportation facilities.

Another objective of the present invention is to provide a building module comprising essentially noncombustible materials.

Another objective of the present invention is to provide a building module that is prefabricated at a factory using the techniques of mass production and automation.

Another objective of the present invention is to provide a building module that is factory prefabricated including an interior finish.

The foregoing objectives and advantages of the invention will appear more fully hereinafter from a consideration of the detailed description which follows,

taken together with the accompanying drawings,

wherein one embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for illustrative purposes only and are not to be considered as defining the limits of the invention.

' DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a two-family dwelling constructed in accordance with the present invention.

FIG. 2 is a plan view showing a typical floor plan for a dwelling as shown in FIG. 1.

' FIG. 3 is a perspective view of a typical building module constructed in accordance with the present invention.

FIG. 4 is an assembly drawing of the module of FIG. 3.

FIG. 5 is a fragmentary perspective view of an end portion of a component used to form the bottom of the module.

FIG. 6 is a fragmentary perspective view of an end portion of a typical component used to form the side walls and top of the module.

FIG. 7 is a fragmentary perspective view of a connection between the top, a longitudinal channel and a side wall.

FIG. 8 is a fragmentary perspective view of a connection between the bottom, a longitudinal channel and a side wall of a module.

FIG. 9 is a fragmentary horizontal section showing a typical side wall construction. 1

FIG. 10 is a fragmentary vertical section showing the construction of a diaphragm separating dwelling units within a module.

FIG. 1 l is a fragmentary vertical section of a dwelling unit taken through a side wall.

FIG. 12 is a fragmentary vertical section taken through a doorway of a dwelling unit.

FIG. 13 is a fragmentary vertical section showing the interconnection between two adjacent modules.

DESCRIPTION OF THE INVENTION Referring to FIGS. 1 & 2, there is shown a typical two-family house constructed from six modules 22 mounted on a concrete slab 24. The individual modules 22 extend across the width of the house so that half of each module forms a portion of one dwelling unit and the other half of the module forms a portion of a second dwelling unit. The dwelling units are separated by a diaphragm assembly 26 positioned centrally in each module.

Each dwelling unit has a first and second floor, the first floor containing the living area, and the second floor the sleepingarea. The dwelling units are arranged in duplex fashion with one family being on the left side and another on the right. Referring to FIG. 2, there is shown the first floor plan for the left dwelling unit, and the second floor plan for the right dwelling unit. The floor plans and the overall dwelling construction will be discussed in more detail subsequently.

Referring to FIG. 3, there is shown an assembled module 22, which illustrates a typical modular construction. The module is tubular with a rectangular cross section having a top 28, sides 30 and a bottom 32 all of which are formed from metal components. The ends of the module are closed with laminated gypsum panels 34, which function to close the module ends and insulate the module interior from the exterior. Four longitudinal channels 36 extend the entire length of the module and are used to connect the top, sides and bottom of the module. The top, sides or bottom of the module may be perforated for installing such things as doorways, windows and staircases and for providing access between modules forming a single dwelling unit. Side wall 30 that forms the front of a house has perforations 38 formed therein for installing doors and perforations 40 for installation of windows.

The outer dimensions of a module cross section are standard and were chosen as l 1 feet 8 inches wide and 9 feet 2 inches high to provide an inside width of 11 feet and a standard ceiling height of 8 feet. Since the module width is less than 12 feet, the module may be conveniently shipped either by rail or highway transportation. The modules are provided in various lengths of 10 feet increments. Module 22 shown in FIG. 3 has a length of 30 feet so that each dwelling unit in the finished house will have a width of 15 feet. It is to be understood that the dimensions previously mentioned and also the dimensions that will subsequently be mentioned were chosen for convenience and should not be considered as limiting the scope of the invention.

Referring to FIG. 4, there is shown an assembly drawing illustrating the assembly of the components forming module 22. The top, sides and bottom are formed of trough-shaped components having a standard modular width and welded together. These components are preferably made from'steel primarily for its strength characteristic. Each component has a modular width of 20 inches, which was chosen so that a fractional component would not be needed to form the standard 10 feet long increments. Half module width components are provided for use wherever gypsum board panels must be mounted to divide dwelling units or to close the end of a module. The half module width components are 9.5 inches wide so that a one-inch air space may be provided between gypsum board panels separating adjacent dwelling units or adjacent modules. The

, air space provides added insulation, sound proofing and fire protection.

Referring to FIG. 5, there is shown an end portion of a typical 20-inch wide bottom component 42 utilized to form the bottom 32 of module 22. Bottom component 42 is made of folded steel sheets having a troughshaped cross section including a base 44 and sloped sides 46. Sides 46 are bent outwardly to form side flanges 48, which are parallel to base 44. Side flanges 48 are bent towards base 44 and extend in a direction perpendicular to the base to form returned portions 49. It is to be noted that the base 44 extends beyond the ends of sides 46, the'purpose for this will be discussed subsequently.

Half modular width bottom components 50 are provided for mounting gypsum .board and have a cross section as shown in FIG. 10.'Components 50 have a width of 9.5 inches and are somewhat similar to the 20-inch bottom components 42, having one sloped side 46, a side flange 48 and returned portion 49. Components 50 differ from components 42 in that one side wall 52 is formed perpendicular to a base 54 so that a channel formed between side wall 52and a returned portion 56 will receive a vertically mounted piece of gypsum board 57, which may bea part of diaphragm 26 as shown in FIG. 10 or an end closing panel 34.

Referring again to FIG. 4, bottom 32 is formed by connecting, by welding or otherwise, portions 49 of adjacent components. The connected components clearly stimulate the standard board and joist construction used in conventional housing. The depth of the bottom components was chosen as 6 3% inches; however, this figure may vary depending upon load requirements and the thickness ofthe steel used.

The top components 58 are formed in a manner somewhat similar to the bottom components 42 in that they have a trough-shaped cross section with side flanges returned. Referring to FIG. 6, there is shown a portion of a top component 58, wherein a base 60 is folded to close the end of the trough. The depth of the top components 58 is 3 V4 inches, but this may be var ied depending on load requirements and the thickness of the steel used. The top components 58 are also of the standard 20-inch modular width and are connected together along the returned side flanges to form the top 28. Half modular width top components 62 are used for mounting gypsum board and have a cross section as shown'in FIG. similar to the cross section of the half modular bottom components 50.

The side components 64 & 65 used to form sides 30 are identical in construction to the ceiling components 58 & 62 and vary only in the thickness of steel used, and the length of the components.

During assembly of the module, the top, sides and bottom are fabricated by welding the components together along and returned portions 49. The returned portions 56 are not welded together for reasons that will become obvious. The bottom 32 is then welded to the longitudinal channels 36 so that the base 44 of the bottom components 42 extends over the top of channels 36 as shown in FIG. 8. Where a diaphragm 26 is to be formed, the half modular width components are spaced apart one inch prior to welding. Welding cleats 66 is formed of angle iron are welded to the inside surfaces of sides 46 and to the inside surface of longitudinal channel 36 to provide added strength. The sides 30 are then placed on top of the floor components 42 so that the extended bases 44 of the bottom components 42 are sandwiched between channels 36 and sides 30. Sides 30 are then welded to bases 44 of bottom components 42.

At this time in the assembly of the module, the gypsum board panels 57, formed of three half-inch thick sheets of gypsum board laminated together to form 1 6 inch thick panels, are slid into the channels defined by the returned portions 56 and sides 52 of the half modular width components. These panels form end closing panels 34 and the diaphragms 26 used to separate dwelling units. The gypsum board'panels provide stiffening for themodule and at the same time provide excellent sound barriers and fire retarders between dwelling units. It is to be noted that diaphragms 26 may be placed any where along the length of the module and the location is not limited to the center portion as illustrated in the drawing. However, wherever the diaphragm is to be located, the half module width components must be used in assembling the top, sides and bottom of the module.

At this point in the module assembly, two upper longitudinal channels 36 are welded to each side of top 28, and the assembly is then placed on top of sides 30 as most clearly shown in FlG.'7 and welded thereto. The basic module, shown in FIG. 3 is then ready for interior finishing, which is also accomplished at the factory. Referring to FIGS. 9 & l0, inside surface of bottom 32 is lined with a five-eighths inch thick particle board 68, which is glue laminated to floor components 42. It is to be understood that any other similar flooring material may be used having a comparable thickness. The ceiling is finished with a three-eighths inch thick gypsum board 72, which is glue laminated to the bottom surface of top 28. In like manner, the interior walls are finished with half-inch thick gypsum board 74, which is glue laminated to the interior of sides 30.

Referring again to FIG. 2, .and more particularly to the upper and lower floor plans of the rear modules where the kitchen and bathroom facilities are located. These upper and lower rear modules are referred to as wet modules in that all the plumbing facilities for the dwelling units are contained in these two modules and are located in plumbing walls 74 formed on each side of a diaphragm 26. The interior plumbing and fixtures are installed at the factory and need only be interconnected between modules and then to the site facilities.

At the building site, the modules are installed on a concrete slab 24 as shown most clearly in FIG. I 1. The longitudinal channels 36 are placed on resilient mounting pads 76, which separate the channels from the concrete slab and function as a gasket to keep water and air from beneath the house. Adjacent modules are interconnected as shown in FIG. 13. A gasket 78 is disposed between the abutting surfaces of channel members 36 of adjacent modules to provide a seal therebetween. The open sides of the upper channels 36 are re inforced by welding reinforcing members 80 across the opening. U shaped brackets 82 are placed over the tops of channels 36 at intervals along the length of the channels and bolts 84 are passed through the brackets and channels to secure the modules together. After the first floor modules are secured together, the second floor modules are placed ontop of the first floor modules. Mounting pads 76 are used to separate the channels 36 of the upper and lower modules and to provide a seal therebetween.

After the modules are interconnected, the exterior surfaces of the house including the sides, top and bottom are insulated by glue laminating insulation board 86 to the outside surfaces of the metal components. A roof structure havinga water resistant top surfaceand formed of components similar to the ceiling components is placed on top of the assembled modules. The roof component is assembled from three sections as seen most clearly in FIG. 1. The front and rear sections 90 & 92 are sloped towards the center of the house as indicatedby the arrows in the figure. The center roof section 94 is sloped towards the sides of the house so that water drains towards down spouts 96.

The interior of the dwelling is finished by installing interior walls 38 as shown in FIG. 2 and metal trim. The interior walls 98 are of simple construction and comprise light weight steel studs with gypsum board glue laminated thereto. The interior walls may be factory installed or installed on site. The access passageways interconnecting adjacent modules is finished as shown in FIG. 13. A floor section 102 of particle board is installed to fill the gap between flooring 68 of adjacent modules. The ceiling and side walls of the passageways between adjacent modules are finished with pressed metal frames 104, which are attached to mounting brackets 106 by self-tapping screws 108. Mounting brackets 106 are welded to channels 36 at the factory prior to site installation.

A typical door installation is shown in FIG. 12, wherein a door jam 114 is connected to a mounting frame 116 by self-tapping screws 118. Mounting frame 116 is welded to channel 36 at factory prior to site installation. Window frames and sills are mounted in a similar manner in the perforations provided for the windows. The exterior of the house is finished with any conventional exterior siding material such as aluminum siding or abestos shingles. After installation of the exterior siding, the door saddle 110 is attached to channel 36 by screws 112.

A floor finish 70, such as linoleum, vinyl or asphalt tiles or carpet is applied to flooring 68 and thereafter base molding 100 is installed around all walls. The floor finish and base molding may also be factory installed depending upon the availability of labor at the site and .the durability of the finish.

in that most of the materials used in construction are non-combustible. The construction of the modules provides for an air space between adjacent modules, which adds substantially to the fire ratings of the walls. It is to be noted that the laminated gypsum board panels forming the diaphrams are separated by a one-inch space thus providing an excellent fire wall between adjacent dwelling units. Likewise, if modules are positioned end to end, an air space will be provided between the gypsum board panels at each end to provide a similar fire wall between the adjacent modules.

A unique characteristic of the tubular module construction taught by the present invention is that the module is rigid and may be made square allowing the interior finish to be applied at the factory using low cost labor. This characteristic results from the use of steel components that are rigid and do not warp as do wood components.

Thus, the present invention provides a building module that may be combined with other such modules to form a building. The module is of such size that it may be manufactured in a factory from standard components, which are assembled using mass production techniques and automation to keep the cost of the building to a minumum. The unique trough-shaped components with returned side flanges provides for maximum strength walls using a minimum of material so that the building unit is self-supporting and has the capability of supporting similar units, thereby facilitating module stacking. The tubular configuration of the module facilitates transportation by rail or highway, while allowing for maximum factory installation of interior finishes, thereby ,reducing the amount of high cost on site construction required. Thus, the present invention provides factory produced building modules capable of being combined in a variety of ways to make houses, hotels, dormitories, hospitals and other kinds of shelter.

What is claimed:

1. A prefabricated building, comprising:

a mounting base;

8 a plurality of independently self-supporting tubular modules having walls comprising bearing surfaces, said modules having a rectangular cross section and arranged to define the shape and size of the building;

bearing joint members independent of connection to each other and each joint member connecting a pair of adjacent walls of the modules; means for securing said modules together; means for closing the ends of the modules including fire resistance insulating panels interconnected with the remainder of the tubular modules so as to form a bearing portion of the building module;

perforations formed in said modules for providing access between modules and for installing doors and windows;

a roof structure overlying said modules; and

means for insulating and weatherproofmg the exterior of said building 2. A prefabricated building module, comprising:

a bottom including a bearing surface;

a pair of sides including a bearing surface;

a top including a bearing surface;

channel members independent from connection to each other and connecting the previously mentioned top, bottom and sides to form a rigid tubular structure having a rectangular cross section; each channel having a longer leg and at least one shorter leg extending substantially perpendicular therefrom and a lip on each shorter leg substantially parallel to the longer leg, each channel providing support for interengagement with each adjacent pair of bottom, sides and top of the module;

panels associated with ends of the tubular structure for closing the same and completing an independently self-supporting module; and

perforations formed in predetermined positions in the tubular structure for providing access to the interior of the module.

3. A building module as described in claim 2, wherein the bearing surfaces of the bottom, sides and top comprises connected, trough-shaped metal components.

4. A building module as described in claim'3, wherein the trough-shaped components have returned side flanges, the returned flanges being connected together to form the bottom, sides and top. i

5. A building module as described in claim 3, wherein the trough-shaped components include a base, sides defining the trough, side flanges essentially parallel to the base and returned portions extending towards the base and perpendicular thereto the returned portions of adjacent components being connected together to form the bottom, top and sides.

6. A building module as described in claim 5, wherein the bases of the bottom components extend beyond the sides and the bases of the top and side components are bent to close the ends of the troughs.

7. A building module as described in claim 6, wherein the extended portions of the bases of the bottom components extend over a channel member at each end and are secured to said channel members, the sides are positioned above the extended portions of the bases of the bottom components and are secured thereto, channel members being attached to the tops of the sides and the top is positioned between channel members and attached thereto.

8. A building module as described in claim 2, additionally comprising an insulating diaphragm positioned within the tubular structure for dividing the interior of the tubular structure into two separate chambers.

' 9. A building module as described in claim 8, wherein the diaphragm comprises two vertically mounted panels spaced apart.

.10. A building module as described in claim 2, wherein the inside of the bottom has a flooring material secured thereto;

the inside of the top has a ceiling material attached to an inside surface thereto; and

the pair of sides have wall material attached to an inside surface thereof.

11. A prefabricated building module, comprising:

a metallic independently self-supporting tubular member having rectangular cross section including a top, bottom and sides, said top, bottom and sides including bearing surfaces; bearing joint members independent of connection to each other and each joint member connecting a pair of adjacent top, bottom and sides of the modules;

fire resistance insulating panel associated with the ends of a tubular member to close the member and define an inner chamber and interconnected with the remainder of the tubular module so as to form a bearing portion of the building module;

perforations formed in predetermined portions of the tubular member to provide access to the inner chamber;

flooring material attached to the inside of the bottom of the tubular member;

wall material attached to the inside of the sides of the tubular member; and

ceiling material attached to the inside of the top of the tubular member.

12. A modular building unit as described in claim 11,

wherein the tubular member is formed of shaped metal components formed and arranged to simulate a joist and board type of construction. 

1. A prefabricated building, comprising: a mounting base; a plurality of independently self-supporting tubular modules having walls comprising bearing surfaces, said modules having a rectangular cross section and arranged to define the shape and size of the building; bearing joint members independent of connection to each other and each joint member connecting a pair of adjacent walls of the modules; means for securing said modules together; means for closing the ends of the modules including fire resistance insulating panels interconnected with the remainder of the tubular modules so as to form a bearing portion of the building module; perforations formed in said modules for providing access between modules and for installing doors and windows; a roof structure overlying said modules; and means for insulating and weatherproofing the exterior of said building.
 2. A prefabricated building module, comprising: a bottom including a bearing surface; a pair of sides including a bearing surface; a top including a bearing surface; channel members independent from connection to each other and connecting the previously mentioned top, bottom and sides to form a rigid tubular structure having a rectangular cross section; each channel having a longer leg and at least one shorter leg extending substantially perpendicular therefrom and a lip on each shorter leg substantially parallel to the longer leg, each channel providing support for interengagement with each adjacent pair of bottom, sides and top of the module; panels associated with ends of the tubular structure for closing the same and completing an independently self-supporting module; and perforations formed in predetermined positions in the tubular structure for providing access to the interior of the module.
 3. A building module as described in claim 2, wherein the bearing surfaces of the bottom, sides and top comprises connected, trough-shaped metal components.
 4. A building module as described in claim 3, wherein the trough-shaped components have returned side flanges, the returned flanges being connected together to form the bottom, sides and top.
 5. A building module as described in claim 3, wherein the trough-shaped components include a base, sides defining the trough, side flanges essentially parallel to the base and returned portions extending towards the base and perpendicular thereto the returned portions of adjacent components being connected together to form the bottom, top and sides.
 6. A building module as described in claim 5, wherein the bases of the bottom components extend beyond the sides and the bases of the top and side components are bent to close the ends of the troughs.
 7. A building module as described in claim 6, wherein the extended portions of the bases of the bottom components extend over a channel member at each end and are secured to said channel members, the sides are positioned aboVe the extended portions of the bases of the bottom components and are secured thereto, channel members being attached to the tops of the sides and the top is positioned between channel members and attached thereto.
 8. A building module as described in claim 2, additionally comprising an insulating diaphragm positioned within the tubular structure for dividing the interior of the tubular structure into two separate chambers.
 9. A building module as described in claim 8, wherein the diaphragm comprises two vertically mounted panels spaced apart.
 10. A building module as described in claim 2, wherein the inside of the bottom has a flooring material secured thereto; the inside of the top has a ceiling material attached to an inside surface thereto; and the pair of sides have wall material attached to an inside surface thereof.
 11. A prefabricated building module, comprising: a metallic independently self-supporting tubular member having rectangular cross section including a top, bottom and sides, said top, bottom and sides including bearing surfaces; bearing joint members independent of connection to each other and each joint member connecting a pair of adjacent top, bottom and sides of the modules; fire resistance insulating panel associated with the ends of a tubular member to close the member and define an inner chamber and interconnected with the remainder of the tubular module so as to form a bearing portion of the building module; perforations formed in predetermined portions of the tubular member to provide access to the inner chamber; flooring material attached to the inside of the bottom of the tubular member; wall material attached to the inside of the sides of the tubular member; and ceiling material attached to the inside of the top of the tubular member.
 12. A modular building unit as described in claim 11, wherein the tubular member is formed of shaped metal components formed and arranged to simulate a joist and board type of construction. 